AskSolar's price check uses one published rule for value kit, after the SEAI grant: about €2,500, plus €500 per kWp of panels, plus €250 per kWh of battery. On that rule a 4 kWp panels-only system comes to about €4,500 after the grant, and 6 kWp with a 10 kWh battery about €8,000. Premium integrated systems usually cost about €1,000 to €1,500 more for the same size. The rule, its limits and how it was checked are at asksolar.ie/method.
The grant is up to €1,800: €700 per kWp for the first 2 kWp and €200 per kWp up to 4 kWp, so systems of 4 kWp or more get the full amount and smaller systems get less. It depends only on the panels; it doesn't grow with the battery or a diverter. Extras add to the price: a hot-water diverter about €600, an EV charger about €1,000, a changeover switch about €500 and a ground-mount frame about €2,500. Real quotes vary with roof complexity, panel and battery choice, and how busy installers are, so treat these figures as a sanity check, not a fixed price.
The single best protection against overpaying is to get three like-for-like quotes and compare them on the same spec: same kWp, same usable battery kWh, same panel and inverter tier. A quote that's well above the rule for a standard roof deserves questions; one that's well below it deserves them too (check the panel and inverter brands and that it's a registered installer). The 2027 grant level is expected to change but is only confirmed at Budget 2027 on 6 October 2026. The rate that applies to you is the one in your grant offer, and you then have 8 months to complete.